Application.ExternalEval - valid js calls -> web page

Unity Engine
1

Using the Application.ExternalEval cammand I am able to open-up, re-size, and kind-of locate the position of where the new page will appear in my game.

I have two (2) issues that I have been fighting with and I am starting to wonder is solutions are even possible.

(1) in locating the page, I can left=100, top=100 or some integer… but I really want to make sure the page is located properly in everyone’s web viewer so I am trying to use screen.height screen.width in the string that I pass to the Application.ExternalEval command but they don’t work.

(2) secondly, I have been trying to send a command to close the open web page page trying variations with both the Application.ExternalEval command Application.ExternalCall and I can’t come up with anything to close the opened web page.

My script:

Code:

if (hudMode == "peripherals") 
   { 
      GUI.skin = customSkinStandard;    
       
      GUILayout.BeginArea (Rect (60,Screen.height - 40,1900,128)); 
      GUILayout.BeginHorizontal (); 
      if (GUILayout.Button ("Turn On Device")) 
      { 
      Application.ExternalEval("window.open('http://www.tech-ufo.com/','microscope','width=640,height=480,left=(screen.width/2)-320,top=(screen.height/2)-240')");  // does NOT work 
      Application.ExternalEval("window.open('http://www.tech-ufo.com/,'microscope','width=640,height=480,left=100,top=100')"); // works but not is exact 
      } 
      if (GUILayout.Button ("Turn Off Device")) 
      { 
      Application.ExternalCall("microscope.close()"); 
      } 
      if (GUILayout.Button ("Return to Classroom")) 
      { 
      camera1.enabled = true; 
      camera2.enabled = false; 
      hudMode = "classroom"; 
      } 
      GUILayout.EndHorizontal ();    
      GUILayout.EndArea(); 
    
}
2

Screen.width and Screen.height will return the size of the webplayer itself, not the dimensions of the screen (although in fullscreen mode, they will be the same).

3

Can the ExternalEval return data passed by the Javascript function?

I am trying to print the variable helloWorld, but I am getting nothing returned, just the Error: Cannot convert void to string, pls help

dt = Application.ExternalEval("getQueryVariable('helloWorld')");
print(dt);
4

Neither ExternalEval nor ExternalCall return anything. The primary reason for this (likely) is because ExternalCall is non-blocking. That is, when you execute it, your program continues running instead of waiting for the browser’s JavaScript function to complete and return a value. It doesn’t explicitely mention this on ExternalEval’s documentation, but I suspect it’s the same (plus as an “eval”, there wouldn’t be a concept of a “return value”)

If you really need to, then perhaps you can have your JavaScript in turn make a SendMessage call back to the Unity player as described here: http://unity3d.com/support/documentation/Manual/Unity%20Web%20Player%20and%20browser%20communication.html

Something like:

//in Unity, script on an object named "MyObject":

function Start()
{
	Application.ExternalCall("ReportQueryVariable", "helloWorld");
}

function OnQueryVariableReceived(var queryData)
{
	var queryTokens : string[] = queryData.Split("|"[0]);
	var variableName : string = queryTokens[0];
	var variableValue : string = queryTokens[1];
	//do stuff
}


//in the web browser

function ReportQueryVariable(var queryVariableName)
{
	var value = GetQueryVariable(queryVariableName);

	var unity = unityObject.getObjectById("UnityContent");
	unity.SendMessage("MyObject", "OnQueryVariableReceived", queryVariableName + "|" + value);
}

The only reason I combine/split the query variable’s name and value with a pipe “|”, is because (if I recall correctly) you can only pass one value back to Unity. And I’m assuming by what you had so far, you wanted it to be a more general-use method. Of course, all the cavaets: wrote it in notepad, no testing, etc.